Fuel-injection system



April 3, 1928. I

L. o. FRENCH FUEL INJECTION SYSTEM Fi led Sept. 4, 1923 E 2 le 64 65 '4 a: 36 o o-o z 3 JNI/ENTOR {Q1 afiuaz Patented Apr. 3, 1928.

UNITED STATES LOUIS O. FRENCH, OI MILWAUKEE, WISCONSIN.

FUEL-INJECTION SYSTEM.

Application filed September 4, 1928. Serial No. 860,840.

The invention relates to fuel injection systems.

Fuel pumps generally are made, either with a constant stroke and a suction valve held I open for varying periods of time to produce a variable delivery, or the plunger itself is given a variable stroke to vary the amount of fuel supplied to the engine, and such pumps are both operated and controlled by 10 mechanical means which vary in complexity.

Where such 'umps are used on injection type engines fbr automotive vehicles, necessitating a. remote control, the controlling mechanism is complicated and is subject to l derangement because of wear on levers and links and other mechanical connections. Furthermore, mechanical controlling mechanism is not readily responsive to changes in load or operating conditions. The ob ect of this 20 invention is to provide a fuel injection system in which the fuel pump is electrically controlled, whereby the amount of fuel and the time of injection thereof may be readily controlled from a distant point, and it is a further object to operate the pump electrically on automotive vehicles or in other situations where a supply of electrical energy is readily available.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:'Fig. 1 is a view, partly in section, of a fuel feeding system embodying the invention; and Fig. 2 is a modification of the construction shown in Figs.-1 and 2. I

In the system shown in Fig. 1 the pump plunger 4 works in the pump body 5 of bronze or other nonmagnetic material, and is driven in any suitable manner, as, for example, by an eccentric strap 6 mounted on an eccentric 7 on a shaft 8 driven by the engine. Fuel is supplied through an inlet port controlled by a suction valve 9 of soft steel or other magnetic material which may, inaddition to its own weight be held closed by a spring 10 and is discharged through a port 11 havinga discharge Valve 12 mounted therein and normally held closed by a spring 13, the fuel being delivered through a pipe 14 to an injector 15 of any suitable construction mounted 'in'the cylinder 15 of the engine. The pump plunger is given a constant stroke and the time" of operation and amount of fuel injected is controlled by electrical means consisting of an electromagnet 16 which, as hereinafter described, attracts and holds the suction valve 9 open so long as said magnet is energized. The coil 17 of the magnet is connected by a. conductor 18 with the fixed contact 19 of a switch, the movable pivoted contact.20 of which is normally held against the fixed contact by a spring 21 and is moved to open position by a timing cam 22 mounted on shaft 23 driven by the engine.

The switch is carried on a member 20 I which is angularly adjustable, either by hand pump so that the suction valve will be held open during the complete working stroke of the pump so as to prevent any delivery of fuel, and from this extreme the other ositions of adjustment of the switch permit of holding the suction valve open for fractional parts of the stroke so that varying amounts of fuel will be delivered, the deenergization of the magnet permitting the suction valve to close and thus determine the time of injection delivery. The suction valve will be held open by the magnet so long as said valve is brought into contact with the magnet during the suction stroke and will continue to be held open during the working stroke if the current is on, but said magnet will not lift the valve against the delivery pressure of the pump so that even if the magnet should be energized after the pump has started its expressing stroke and the suction valve is closed the suction valve will remain closed. As the action of the pump on its suction stroke lifts the suction valve, said valve will be readily brought into magnetic or attractive relation with the core of the magnet. As the magnet is so located as to act directly upon the relatively light suction valve, a very sensitive action is secured, since only the inertia of a relatively small and light part has to be overcome and hence the pump will accurately handle and deliver very small quantities of fuel;

In the system shown in Fig. 2 the pump plunger 45 is given a constant stroke by means of a solenoid 46 and the suction valve 47 is held open for varying periods of time by means of an electromagnet 48. The time of operation of the plunger is determined by the closing of the engine-operated switch 49 and the time of closing the suction valve by the opening of an engine-operated switch 50. Both switches 49 and 50 are similar to that previously described and are adjustable so that the time and amount of injection may be varied. A battery 51, or suitable source of electrical energy, supplies current to the magnets. A conductor 52 connects one side of the battery with one end of the coil of the magnet 48 and the other end of said coil is connected by a conductor 53 with the fixed contact of the switch 50. A conductor 54 connects the movable switch arm of switch 50 with the other side of the battery so that when the switch 50 is closed the magnet 48 will be energized. A conductor 55 connects one side ofthe batterywith one end of the coil of the solenoid 46 and the other end of said coil is connected by a conductor 56 with the fixed contact of the switch 49. A conductor 57 connects the movable switch arm of the switch 49 with the other side of the battery so that when the switch. 49 is closed the coil of the solenoid 46 will be energized. A manually-controlled cut-out switch 58 is preferably included in the solenoid circuit. For priming purposes one side of the battery may be connected by conductors 59 and 60 and a push buttom switch 61 with theconductor 56 which with the conductor 55 'forms a circuit to energize the solenoid when the switch 61 is closed and starting switch 58 is closed. With this construction the time of injection may be varied by the adjustment of the switch 49 and the amount of injection for any given time may be varied by the adjustment of the switch 50.

Each of the switches may have a condenser 62 bridged across the contacts to prevent arcing. Q

The pump shown in Fig. ,2 is similar to that shown in Fig. 1 and is provided with a discharge valve 63 delivering fuel through a pipe 64 to an injector 65 in the cylinder head 66 of the engine. r

The drive for the timing cams by the engine may be such as are employed for driving the breaker and distributors of several well known ignition systems and for the purpose of illustration I show the engine 72 in Fig. 1 having its crank-shaft 73 connected by a suitable gearing connection 74 with the shaft 23 with the casing 20 mounted for rotation relative to said shaft 23.

The invention is particularly applicable to solid fuel'injection systems for internal combustion engines wherein the injection of fuel occurs during the working stroke of the pump, as by the unseating of a valve 75,

normally held against its seat by a spring 76, when the pump is making its workin stroke so that fuel is delivered past sai valve through a nozzle 77 into the cylinder of the engine.

I desire it to be understood that this invention is not to be limited to any specific form or arrangement of parts except in so far as such limitations are included in the claims.

lVhat I claim as my invention is 1. In a fuel injection system, the combination with a pump having a valve controlling passage to its fuel supply, of an electromagnet so located as to act directly on said valve for moving it inone direction to control the amount of fuel delivered by the pump, means for energizing said'magnet, and adjustable engine-controlled means for trolling the operation of said energizing means. I

2. In a fuel injection system, the combination with a pump having a suction valve, of an electromagnet so located as to act directly on said valve for holding it open, means for energizing said magnet, and adjustable engine-controlled means for con trolling the operation of said energizing means.

3. In a fuel injection system, the combination with a pump having a suction valve, of an electrical circuit including a source of current, a switch and an electro-magnet acting to hold said suction valve open and an engine-driven cam for o ening said switch, said cam permitting sai switch to be held closed for more than one complete stroke of the pump so that the suction valve will be held open during the com lete working stroke of the pump for no do 'very and beingrelatively angularly adjustable with respect to the switc 1 to vary the time of energization of said magnet between no delivery and full delivery and thereby vary the amount of fuel delivered by the pump.

4. In a fuel injection system, the combination with a pump including a plunger and suction valve, of electrical means for operating said plun er, and adjustably timed electrical means or holding said suction valve open during a portion of the stroke of said plunger. a

5. In a fuel injection system, the combination with a pump having a suction valve, of an electromagnet having one of its poles arranged closely to and in magnetically attractive relation with the head end of said valve to act on said valve to control the amount of fuel delivered by the pump, means for energizing said magnet, and adjustable engine-controlled means for controlling the operation of said energizing means.

. 6. In a fuel injection system, the combination with an injection type engine, a pump including an expressing member and suction valve of adjustably-timed electrical means for operating said member at any time in the cycle of the engine, and adjustablytimed electrical means for holding said suction valve open for varying periods during the expressing stroke of sald member.

- 7. In a fuel injection system for internal combustion engines, the combination with a fuel injector, of a pump to supply fuel there- 10 t0 and including charge-determining means,

of electrical means for operating said chargedetermining means, and a plurality of relatively adjustable engine-operated controls for said electrical means whereby the time of injection during the engines cycle and the amount of fuel injected durin any one cycle of the engine ma be varie In testimony whereo I aflix my signature.

LOUIS O. F BEN CH. 

